Telephone-exchange system



Feb. 26, 1924. 1,484,751

W. P. ANDRXCK TELEPHONE EXCHANGE SYSTEM 2 Sheets-Sheet 1 Filed June 1922 Feh. 26 1924. 1,484,751

w. P. ANDRICK TELEPHONE EXCHANGE SYSTEM Filed June 8. 1922 2 Sheets-Sheet 2 k), ,zwy

Patented Feb. 2%,, i224.

WALLACE P. ANDRICK, 0F I-IOHOKUS, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed June 8, 1922. Serial 1%. 566,739.

To all whom it may concern:

Be it known that I, WALLACE P. ANnRrcK, a citizen of the United States, residing at Hohokus, in the county of Bergen, State of New Jersey, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to systems wherein a plurality of associated subscribers lines may be connectedto a central station and simultaneously signalled and simultaneously conversed with from said station.

The system that is to be hereinafter described in detail has awide range of use and is particularly applicable in connection with large business establishments and mu nicipal departments. In such instances as those specified, it is frequently desirable and often necessary for an executive or officer to be constantly in communication with a number of his subordinates, and in most cases the character of the information or instructions to be issued is such as to demand its immediate transmission to all of the subordinates.

In the applicants system, the foregoing requirements are met and the inconveniences encountered in establishing an individual connection with each subordinate are obviated.

A copending application of Elbert W. Thurston and Phillip M. Chase, Serial No. 568,401, filed June 15, 1922, discloses a system which is adapted to group a plurality of subscribers lines and simultaneously connect them to,a common central station.

There is also disclosed in the aforementioned copending application a method and means for broadcasting a message to the stations on such subscribers lines wherein transmission from the stations is prevented during transmission by the central office operator.

It is an object of this invention to improve upon the system disclosed in the above-mentioned application by reducing the amount of apparatus required, by employing a single line relay for indicating individual incoming calls and individual responses to grouped calls.

In accordance with a feature of the invention a switching means is provided to selectively determine whether the line relay will produce a signal indicating an individual incoming call or an individual response to a grouped outgoing call.

' Other features, not specifically mentioned, will. readily appear from the following detailed description and by reference to the accompanying drawings, in which Fig. 1 shows a plurality of groups of two party lines, each group terminating in a common grouping jack at a central office and each line terminating in a plurality of individual jacks. Fig. 2 shows a plurality of multiple plugs associated with a common cord circuit.

Referring now to the drawings, a group of two party lines is shown terminating at. a grouping position of a central ofiice in a grouping jack 12. Each line of said group terminates in a jack, such as 3 and 13 at a regular answering position and in a jack, such as 14 and 15 at a grouping position. Another set of two party lines is shown terminating at a grouping position of a central oflice in jack 11 and each line of said group terminating in a jack, such as 16, 17 and 18 at the regular answering position and in a jack, such as 19, 20 and 21 at the grouping position. Each line and each group of lines is adapted to be connected through a cord circuit C to an operators telephone set as shown. By the insertion of any plug, such as 2, of cord circuit C in any jack, such as 14 or 19, the operator may converse individually with the subscribers associated with these jacks or by inserting the same plug in a jack, such as 11 or 12, the operator effects a grouping connection between her set and all the lines associated with these jacks.

In response to an individual call, the subscriber actuates the regular line relay such as 7 to energize a signal lamp such as 23, at a regular answering position, whereas, in response to a grouping call, the same line relay is operated to energize a signal lamp, such as 60, at a grouping position. To accomplish the latter result, it is evident that the grouping operator must actuate keys such as 24 to switch the control of the line relay from signal lamp 23 to signal lamp 60.

The invention will be more fully understood from the following detailed description of its functions andvarious conditions in the system disclosed.

Upon initiation of a call by one of the subscribers, such as subscriber A on a line, such as 1,'the line relay 7 will be operated in the usualmannerover a circuit extending from battery, through the lower winding of relay 7, lower contact of relay 5, left-hand normal contact of relay 10, resistance 51, apparatus at station A, resistance 50, right-hand normal contact of relay 10, upper contact of relay 5, upper winding of relay 7 to ground. If key 24 is in its normal position lamp 23 associated with jack 3 at the regular answering position will be illuminated over an obvious path. Such a call will behandled by the operator at. such a position in the usual manner. g a

An individual connection to a subscriber, such as A. on line 1, may also be made by the grouping operator. Such an arrangement is desirable in casethe subscriber does not respond to a previous, grouping call and when it is essential that the subscriber should be included in a common connection. To this end, the grouping operator inserts plug 2, or any plug associated with her set, into jack 14, operates key 24 associated with the desired, line, and actuates ringing key 4. The operation of ringing key 4 establishes a circuit for cut-oil relay 5 from battery 6, lower alternate contact of key 4, sleeve contacts of plug 2 and jack 14, winding of relay 5 to ground. The operation of relay 5 disconnects the regular line relay 7 from the subscribers line 1. Upon the actuation of key 4, relay 8 is energized over an obvious circuit from the battery 6. Relay 8, in operating, closes its contacts and connects the ringing current source 9 to the ring conductor, and ground to the tip conductor of plug 2. The bell associated with the subscriber A on line 1 is actuated over the following circuit: ringing current source 9, upper alternate contact of relay 8, ring con tacts of plug 2 and jack 14, left normal contact of relay 10, the bell at station A to ground. ln'response tothis signal, the subscriber at station A removes the receiver and bridges the conductors o1 line 1 in the usual manner. The operator returns the key 4 to normal thereby deenergizing relay 8 and cut-oil relay 5, whereupon line relay 7 isvagain connected to the line 1. In bridging the conductors of line 1, the following circuit is established for line relay 7: from grounded battery 22, lower winding of relay 7, lower normal contact of relay 5, leftnormal contact of relay 10, resistance 51, telephone set at station A, resistance 50, right normal contact of relay 10, upper normal contact of relay 5, upper winding of relay 7 to ground, whereupon relay 7 is energized meager completing an obvious circuit for the signal lamp 60 by way of the upper normal contact of grouping key 24. The operator, noting the illumination of lamp 60 actuates the talking key 25 and establishes a circuit for relay 26 from battery 6, normal contacts of ringing keys 4 and 43, upper alternate con tact of key 25, winding of relay'26 to ground. 1n operating, relay 26 closes its contacts and connects the operators telephone with the tip and ring conductors of plug 2. By the operation of key 25, the following circuit is also established, from battery 6, normal contacts of keys 4 and 43, lower alternate contact of key 25, sleeve contacts of plug 2 and jack 14, winding of relay 5to ground, whereuponrelay 5 operates and disconnects line relay 7 from the line 1, thereby interrupting the circuit for lamp 60. Station A. and the operators telephone are now in telephonic connection. Upon the completion of the conversation, the subscriber replaces his receiverand the operator withdraws the plug 2 from jack 14, therebyrestoring the apparatus to normal In the event that a message of common interest to the subscribers on lines 27, 28 and 29 is to be transmitted thereto by the operator, the procedure is as follows: a The operator actuates grouping keys 34, 35 and 36, inserts plug 2 or any other plug associated with the cord circuit G into the grouping jack 11 and operates ringing key 4, thereby establishing an energizing circuit for relay 30 over an obvious path. Relay 30 closes its contact and establishes av circuit for each of the relays 31, 32 and 33,

one of which circuits is traced from grounded battery 37, lower alternate contact of key 34, winding of relay 31, alternate contact of relay 30 to ground. The circuits for relays 32 and 33 are similarto that just traced for relay 31. ,Relays 31, 32 and 33, in operating, connect the tip and ring conductors of jack 11 with the lines 29, 28 and 27 respectively. When key 4 is operated, a circuit for relay 8 is established whereupon the ringing current source 9 is connected to the ring contact 01 plug 2 and current is sent over thevgrouped lines 27, 28 and 29 and the bells located at the stations, designated. as A stations, will be operated. The operator then restores key 4 to normal and actuates: the second ringing key 43 whereupon a circuit is established for relay 39 over an obvious path. Relay 39,, in operate ing, connects through its lower alternate lines is efiected. a,

Upon hearing the calling signals, the subscribers remove their respective receivers and effect the illumination of lamps 40, 41

and 42 at a grouping position. The illumination of lamp 40 will be traced and will suflice to describe the manner in which lamps 41 and 42 are also illuminated. The operator returns the ringingkey 43 to normal whereupon relay 30 is deenergized and the circuits for relays 31, 32 and 33 are interrupted and the lines 29, 28 and 27, respectively, are again connected to the line relays 44, 45 and 46, respectively. The subscriber on line 27, in removing the receiver, establishes an energizing circuit for relay 46 over an obvious path whereupon lamp 40 is illuminated from battery 47 filament of lamp '40, upper alternate contact of key 36, and contact of relay 46 to ground. In this manner, the operator is notified of the response of the subscribers.

If for any reason neither subscriber on a line (for example on line 27) fails to respond, the operator withdraws the plug from jack 11, inserts it into jack 19 and operates keys 4 and 43 alternately as before mentioned. In this manner, each subscriber may be signalled individually at a grouping position.

Assuming that all the subscribers have responded and plug 2 remains in jack 11, the operator actuates talking key 25 thereupon energizing relays 26 and 30 over obvious paths. By the operation of relay 26, the operators telephone is connected to the tip and ring contacts of plug 2. The operation of relay 30 again causes the association of the lines 27, 28 and 29 with the tip and ring contacts of jack 11 and interrupts the circuits for line relays 46, 45 and 44 whereupon the lamps 40, 41 and 42, respectively, are extinguished. The operator is now in position to deliver general orders or information to the grouped subscribers.

If it is not necessary for the grouped subscribers to reply, the operator may disconnect the battery supply 49 from the grouped lines by actuating key 48 thereby excluding all possible noise which might otherwise be introduced by the station transmitters while a general order is being delivered.

It is obvious that the lines associated with jack 12 or any other grouping jack may be grouped in the same manner as heretofore described in connection with the lines associated with jack 11, each group having a relay corresponding to relay 30.

The functions and operations of the relays not designated by reference characters nor mentioned in the foregoing description but shown in the cord circuit C are obvious and will be clearly understood by those skilled in the art.

By the circuit arrangement disclosed and described, it is obvious that the number of subscribers lines that may be grouped for simultaneous conversation is unlimited.

The resistances 50 and 51 through which ringing and talking current is supplied to the associated lines perform the useful function of effecting an approximate equalizat'ion of current flow, regardless of the length of the lines. For a common ring ing and talking system this is very desirable since a short circuit or ground on one or more lines might shunt away sufiicient current to render impossible the proper functioning of all lines of the associated group.

What is claimed is:

1. In a telephone system, a plurality of lines, each of said lines terminating at a grouping position and at an answering position, a signaling device for each of said lines at each of said positions, means for signaling all of said lines as a group, and means for actuating the signaling devices at the grouping position to denote response to the grouping signal and at the answering position to denote a call from the station.

2. In a telephone system, a plurality of lines, each of said lines terminating at a grouping position and at an answering position, a subscribers station for each of said lines, a signaling device for each of said lines at each of said positions, means for signaling all of said lines as a group, and means including a line relay controlled from the subscribers station for actuating the corresponding signaling device at the grouping position to denote response to the grouping signal and at an answering position to denote a call from the station.

3. In a telephone system, a plurality of lines, each of said lines terminating at a grouping position and at an answering position, a subscribers station for each of said lines, a signaling device for each of said lines at each of said positions, means for signaling all of said lines as a group, means associated with a line and controlled from the subscribers station, and switching means cooperating therewith when in one position to control the signaling device at the grouping position to denote response to the grouping signal and when in another position to actuate the signaling device at the answering position to denote a call from said subscribers station.

4. In a telephone system, a plurality of lines, each of said lines terminating at a grouping position and at an answering position, a subscribers station for each of said lines, a signaling device for each of said lines at each of said positions, means for signaling all of said lines as a group, means at the grouping position for signaling each of said lines individually, means associated with each of said lines and controlled from the corresponding subscribers station,

switching means cooperating therewith when in one position to control the signaling device at the grouping position and when in another position to control the signaling 5 device at the answering position, and means associated with each of said lines for disassociating the signaling devices from the In wltness whereof; I hereunto subscribe my name this 7th day of June; A. D., 1922.

WALLACE P. ANDRICK. 

